Needle selecting mechanism for flat knitting machines

ABSTRACT

In a flat knitting machine, a needle selecting mechanism comprises electromagnets energizable at the dictates of the pattern, movable with the machine carriage and serving as selectors for needles or needle-actuating jacks (knitting instrumentalities) displaceably mounted in the slots of the needle beds. Armatures associated with the knitting instrumentalities are movable toward the selector electromagnets against spring influence by means of presser cam parts. The poles of a plurality of selector electromagnets extend over a plurality of needle bed slots in the direction of travel of the machine carriage, and are arranged at each selection zone of the cambox such that the pole of a single magnet is located between the poles of a pair of spaced electrically connected magnets. The knitting instrumentalities are of two forms, one form having a single central armature bearing portion for cooperation with the single electromagnets, and the other form having two symmetrically spaced armature bearing portions for cooperation with the pairs of spaced selector electromagnets. The knitting instrumentalities of the two forms are alternately arranged in successive needle slots.

United States Patent r19] 7 Kazmeier et al.

[ June 25, 1974 NEEDLE SELECTING MECHANISM FOR FLAT KNITTING MACHINES [75] Inventors: Giinther Kazmeier; Wilhelm Hadam, both of Reutlingen,

Germany I [73] Assignee: II. Stoll and Company, Reutlingen,

Germany [22] Filed: Feb. 27, 1973 [21] Appl No.: 336,237

[52 us. CL... 66/75, 66/154 A Primary ExamineF-Ronald Feldbaum Attorney. Agent, or Firm-Larson, Taylor & Hinds [57] ABSTRACT In a flat knitting machine, a needle selecting mechanism comprises electromagnets energizable at the dictates of the pattern, movable with the machine carriage and serving asselectors for needles or needleactuating jacks (knitting instrumentalities) displaceably mounted in the slots of the needle beds. Armature's associated with the knitting instrumentalities are movable toward the selector electromagnets against spring influence by means of presser cam parts. The poles of a plurality of selector electromagnets extend over a plurality of needle bed slots in the direction of travel of the machine carriage, and are arranged at each selection zone of the cambox such that the pole of a single magnet is located between the poles of a pair of spaced electrically connected magnets. The knitting instrumentalities are of two forms, one form having a single central armature bearing portion for cooperation with the single electromagnets, and the other form having two symmetrically spaced armature bearing portions for cooperation with the pairs of spaced selector electromagnets. The knitting instrumentalities of the two forms are alternately arranged in successive needle slots.

6 Claims, 4 Drawing Figures PATENTEUJUNZSIHH' sum 2 ur 2 3 a ma W @N om I. NEEDLE SELECTING MECHANISM FOR FLAT KNITTING MACHINES This invention relates'to a needleselecting mechanism for flat knitting machines, and has reference particularly to such mechanism of the kind comprising electromagnets energisable at the dictates of the pattern, movable with the machine carriage and serving as selectors for needles or needle-actuating jacks displaceably mounted in the slots of the needle beds, and wherein armatures associated with the needles or needle-actuating jacks are movable towards the selector electromagnets against spring influence bymeans of presser cam parts. i

ln a known form of needle selecting mechanism of this kind only one electromagnet is provided at the selection part of the cambox, and this acts on all of a series of armatures associated with the needles. This means that there is only a short time availablefor selecting the needles unless the rate of travel of the carriage is reduced to afford sufficient time for the selection. Moreover, having regard to the fact that the carriage recjprocates and as a consequence has a rate of travel which is not uniform, problems may arise in the case of the aforementioned known form of mechanism in respect of the synchronising of the movement of the carriage and the emission of successive impulses.

7 2 trol butts adapted to be acted upon by presser cam parts.

This symmetrical construction of the armature jacks secures a particularly reliable functioning thereof. Moreover, the weight and the dimensions of the armature jacks are small because they are guided in duplicated fashion and loaded symmetrically by virtue of the symmetrical arrangement of their butts. Added to this, a parallel movement of the armature jacks, which does not involve any rocking thereof, is achieved by their symmetrical form, thereby ensuring an effective application of the armature portions of the said jacks against the poles of the relevant selector electro-magnets. The armature jacks are safely held down even after a light engagement by the presser cam parts, and this avoids the use of space-consuming magnetic-holding tracks following the selector electro-magnets.

In a convenient embodiment of the invention the selector electromagnets of each group are arranged beneath the needle bed and project into at least one rec'ess in the said bed in communication with the bottoms of the appropriate needle slots. This allows for a compact construction of the machine carriage.

Needle selecting mechanisms are also known in t which a plurality of selector electromagnets of the same height are arranged at a selection zone in the direction of travel of the carriage. in these further known arrangements, however, the electromagnets are arranged one above'another and act onneedle or jack butts disposed in a staggered relation. But unfortunately the advantage achieved in these mechanisms in respect of increased operating time for the electromagnets is offset by the disadvantage that such electromagnets take up a comparatively, large amount of space on the machine carriage, particularly in a direction transverse to that of the carriage movement, and they consequently involve comparatively large forces of inertia at the carriage and the needles or jacks.

' It isthe object of the present invention to provide a needle selecting mechanism of the kind herein set forth which, besides being of a simple construction caters for an effective needle selection in conjunction with high carriage speeds.

The improved needle selecting mechanism constituting this invention is characterised in that poles of a plurality of selector electro-mag nets extend to the same height each over a plurality of needle bed slots in the direction of travel of the machine carriage and are so arranged at each selection zone of the cambox that the pole of a single electromagnet is located between the poles of a pair of spaced electro-magnets, and in that armatures associated with successive needles or neerile-actuating jackstboth of which are hereafter sometimes referred to generically as knitting instrumentalities) are adapted to co-operate with the single electromagnets and the pairs of spaced electro-magnets alternately.

Advantageously, the armatures associated with the needles or needle-actuating jacks may be in the form of symmetrically formed armature jacks each of which is provided at opposite sides ofa central medial line in its plane of symmetry with restoring springs and with con- According to another aspect of the invention the se lector electromagnets can be energised to hold armature jacks in the projected position over a section of travel of the carriage'corresponding at least to the length of a selection zone in the cambox. Thus, two adjacent and differently formed armature jacks can be selected independently of one another over a selection zone of two needle divisions, and this selection zone is sufficient for an effective needle selection in both directions of travel of the machine carriage. An armature 5 jack not held by any one selector electromagnet after one and a half needle divisions is already disposed with its control butts safely beneath the next following advancing cam parts.

In order that the invention may be more clearly understood and readily carried into practical effect, a specific embodiment thereof will now be described with reference to the accompanying diagrammatic drawings, wherein,

FIG. 1 is a plan view of onehalf of a cam system on the machine carriage provided for operating the armature jacks,

' H6. 2 is a cross-section taken on the line ll ll of HO. 1 through a needle slot occupied by a first form of armature jack in accordance with this invention, this jack being shown bearing against a pair of selector electromagnets.

FIG. 3 is a similar cross-section taken on the line lll III of PK]. 1 through a needle slot which is occupied by a second form of armature jack in accordance with the invention, and

F IG. 4 is a highly diagrammatic section through the needle bed and the cam plate on the machine carriage taken on the line lV IV of FIG. 1.

In FIG. 1 the needle slots 11 in a needle bed 10 are indicated by transverse lines drawn parallel to one another. Moreover, shown in each of a number of these needle slots are two control butts 121 and 122 of a symmetrically-formed needle actuator constituted by an armature jack. These armature jacks are seen in FIGS. 2 and 3; of these there are two sorts 12a and 12b, one sort or the other being provided in each needle slot 1 ll In FIG. 1 presser cam parts 13, 14, and 16, with dotted contours for action on the control butts 121 and 122 of the armature jacks 12a and 12b, are illustrated as components of the cam system of the machine carriage. FIG. 4 shows the profile of the presser cam part 14 depicted in common with the presser cam part 13 directly in advance of the active area of the selector electromagnets 18a and 18b, as regarded in the direction of travel of the machine carriage'indicated by the arrow 17 in FIG. 1, energisation of these magnets being programmed in accordance with a required pattern of knitting. The presser cam parts 13 and 14 serve to move the oncoming armature jacks 12a and 12b, with heir control butts 121 and 122, against the action of corresponding restoring springs 19 and 20. The two sorts of armature jacks 12a and 12b are arranged alternately in successive needle slots 11. The armature jacks 120, each having two symmetrically-disposed bearing parts 124 and 125 (see FIG. 2) are influenced by the pairs of selector electromagnets 18a and 210, whereas the armature jacks 12b each having a central bearing part 123 (see FIG. 3), are influenced by the single selector electromagnets 18b and 21b.

Thus, in FIG. 1 there are shown, in addition to the selector electromagnets 18a and 18b which effect the projection of needles into the knitting position, the selector electro-magnets 21a and 21b which succeed them in the cam carriage direction 17, and move the needles into the tucking position. Associated with the electromagnets 21a and 21b is the pair of presser cam parts 15 and 16 for positively introducing all the armature jacks.

Also illustrated in FIG. 1 are cam parts 22, 23 and 24, 25 arranged in pairs which are, at required times, effective in the active area of the selector electromagnets 18a, 18b or 21a, 21b to bring about a longitudinal shifting of armature jacks by action on the control butts 121 and 122 of these armature jacks 12a and 12b which have not been held by the selector electromagnets concerned and are freed again by the presser cam parts 13, 14 or 15, 16 (see FIG. 4). 7

It is to be clearly understood that FIG. 1 shows only half of the symmetrically laid'out cam system on the machine carriage. The other half of the said system which likewise has two groups of selector electromagnets. and which is effective during the stroke of the carriage in a direction opposite to that indicated by the arrow 17, is not illustrated.

The cross sectional views constituting FIGS. 2 and 3 disclose the two forms of armature jacks 12a and 12b, and it will be seen that the cam plate 26 of the machine carriage (which is not illustrated as regards its other parts) is connected through the medium of a coupling bar 27 with a carrier plate 28 for the selector electromagnets. Whilst the cam plate 26 is located above the needle bed 10, the magnet carrier plate 28 is disposed beneath the said bed, with the interposed coupling bar 27 clear of the relevant margin of the latter. The selector electromagnets, of which only 180 and 18b are visible in FIGS. 2 and 3 project into a slotted recess 31 formed in the needle bed 10, this recess communicating with the bottom of the needle slots 11 in the area of the armature jacks 12a and 12b arranged therein. As has already been stated, the armature jacks 12a and 12h are of symmetrical form and differ from one another only in their bearing parts 123, 124 and 125. The restoring springs 19 and are in the form of leaf springs which are arranged symmetrically with respect to the said bearing parts of the armature jacks 12a and 12b and are secured at their ends in these jacks. The free end portions of the leaf springs 19 and 20 are supported on the bottoms of the needle slots 11.

' FIG. 2 shows an armature jack 12a in a position in which its control butts 121 and 122 have run on to the presser cam parts 13 and 14 of the machine carriage so that this armature jack is pressed into the needle guide slot 11 against the force of springs 19 and 20, and its bearing parts 124, are brought into the effective area of the selector electromagnets 18a. In this position of the armature jack the control butts 121 and 122 are brought out of the effective range of the next following projecting cam parts 22 and 23, as can be seen from FIG. 4. If the selector electromagnets 18a which are always electrically connected together are energised, the armature jack 12a will be held in the depressed position even after the presser cam parts 13 and 14 have passed and the control butts 121 and 122 are not engaged by the advancing cam parts 22 and 23. The armature jack 12a remains in its starting position and an adjoining needle-actuating jack 29, which has been indicated in dotted lines, likewise remains in a raised position so that the associated needle is not affected and not advanced into the knitting position.

Conversely, if the selector electromagnets 18a or 18b are not energised, the armature jacks 12a and 12b. after release by the presser cam parts 13 and 14 are lifted again within the needle slot 11 by the restoring springs 19 and 20, so that their control butts 121 and 122 are brought into the range of the following advancing cam parts 22 and 23 and the armature jacks are shifted into an operative position. This is illustrated in FIG. 3 in relation to an armature jack 12b which can be influenced at its central bearing part 123 by the selector electromagnets 18b and 21b. The needleactuating jacks 29 can also be shifted in the needle slots 11 by the armature jacks 12a and 12b so that their control butts 30 pass into the range of cam parts (not shown, but of known form) which bring about advancement of the needle-actuating jacks 29 and hence also of the associated needles (not shown) into the knitting position and also a succeeding return of the needles and needle-actuating jacks. together with the corresponding armature jacks into their starting positions.

A similar selection process is applied to the armature jacks 12a and 12b in the zone of the selector electromagnets 2la and 21b and the associated presser cam parts 15, 16 and the projecting cam parts 24 and 25, this particular process determining which of the needles are advanced into the tucking position.

The symmetrical construction of the armature jacks 12a and 12b ensures an accurate operation of these jacks, even when they have imparted thereto only a relatively small amount of operating movement, so that the shifting of the armature jacks in a direction at right angles to the needle bed 10 and against the force of the restoring springs 19 and 20, can be kept to less than 2 mms.

What we claim is:

1. In a flat knitting machine, a needle selecting mechanism of the kind comprising electromagnets energisable at the dictates of the pattern, movable with the machine carriage and serving as selectors for knitting instrumentalities displaceably mounted in the slots of the needle beds, and wherein armatures associated with the knitting instrumentalities are movable towards the seselection zone of the cambox such that the poles of one electromagnet are located between the poles of another electromagnet, and in that the knitting instrumentalities are of two different forms, viz. one form having a single central armature bearing portion for cooperation with the one electromagnet and the other form having two symmetrically spaced armature bearing portions for cooperation with the poles of said other electromagnet, the knitting instrumentalities of the two forms being alternately arranged in successive needle slots.

2. A needle selecting mechanism according to claim 1, wherein the armature's associated with the knitting instrumentalities are in the form of separate armature jacksl 3. A needle selecting mechanism according to claim 2, wherein each of the separate armature jacks is symmetrically fonned andprovided at opposite sides of a central media] line in its plane of symmetry with restoring springs and with control butts adapted to be acted upon by presser cam parts.

4. A needle selecting mechanism according to claim 1, wherein the selector electromagnets of each group are arranged beneath a needle bed and project into at least-one recess in the bed in communication with the bottoms of the appropriate needle slots therein.

5. A needle selecting mechanism according to claim 2, wherein the selector electromagnets are energisable to hold down the relevant armature jacks over a portion of the travel of the machine carriage corresponding at least to the length of a selection zone in the cambox.

6. A needle selecting mechanism according to claim 2, wherein each half of the cam system on the machine carriage is equipped with two groups of selector electromagnets for initiating, through the medium of said armature jacks, advancing movements of needles respectively to knit and to tuck during a traverse of the reciprocatory cam carriage in the relevant direction. 

1. In a flat knitting machine, a needle selecting mechanism of the kind comprising electromagnets energisable at the dictates of the pattern, movable with the machine carriage and serving as selectors for knitting instrumentalities displaceably mounted in the slots of the needle beds, and wherein armatures associated with the knitting instrumentalities are movable towards the selector electromagnets against spring influence by means of presser cam parts, said selecting mechanism being characterized in that poles of a plurality of selector electromagnets extend, at the same height each, over a plurality of neEdle bed slots in the direction of travel of the machine carriage and are disposed at each selection zone of the cambox such that the poles of one electromagnet are located between the poles of another electromagnet, and in that the knitting instrumentalities are of two different forms, viz. one form having a single central armature bearing portion for cooperation with the one electromagnet and the other form having two symmetrically spaced armature bearing portions for cooperation with the poles of said other electromagnet, the knitting instrumentalities of the two forms being alternately arranged in successive needle slots.
 2. A needle selecting mechanism according to claim 1, wherein the armatures associated with the knitting instrumentalities are in the form of separate armature jacks.
 3. A needle selecting mechanism according to claim 2, wherein each of the separate armature jacks is symmetrically formed and provided at opposite sides of a central medial line in its plane of symmetry with restoring springs and with control butts adapted to be acted upon by presser cam parts.
 4. A needle selecting mechanism according to claim 1, wherein the selector electromagnets of each group are arranged beneath a needle bed and project into at least one recess in the bed in communication with the bottoms of the appropriate needle slots therein.
 5. A needle selecting mechanism according to claim 2, wherein the selector electromagnets are energisable to hold down the relevant armature jacks over a portion of the travel of the machine carriage corresponding at least to the length of a selection zone in the cambox.
 6. A needle selecting mechanism according to claim 2, wherein each half of the cam system on the machine carriage is equipped with two groups of selector electromagnets for initiating, through the medium of said armature jacks, advancing movements of needles respectively to knit and to tuck during a traverse of the reciprocatory cam carriage in the relevant direction. 